Various communication networks exist for enabling distributed devices to communicate and pass information between one another. Networks usually are classified based upon three properties: topology, protocol, and architecture. The topology of a network specifies the geometric arrangement of the network. Common topologies are a bus, ring, and star. The protocol specifies a common set of rules and signals the devices on the network use to communicate. The architecture of a network refers to the network design. There are two major types of network architecture: peer-to-peer and client-server. In a peer-to-peer networking configuration, there is no central server, and devices simply connect with each other in a workgroup to share files, printers, and Internet access. In a client-server architecture, there usually is a central server, with which all of the devices register. The central server usually provides a variety of services, including centrally routed Internet access, e-mail, file sharing, and printer access, as well as ensuring security across the network. A network architecture also may be characterized as being open (i.e., the specifications are available to the public) or closed (i.e., the specifications are proprietary).
Recently, efforts to deliver data to distributed devices have focused on providing personalized and localized services. For example, context aware mobile telephones have been developed to access data through low power, short range base stations in places, such as shopping malls to provide location-specific information, such as local maps and information about nearby shops and restaurants. A context aware mobile telephone may be configured to filter the information received from base stations according to pre-stored user preferences so that the user will be alerted only if an item of data of particular interest has been received.
U.S. Pat. No. 5,835,861 describes a wireless telephone system in which a wireless telephone may retrieve the telephone number of a vendor by transmitting a prompt signal to an active advertisement source, which in turn transmits a response signal containing the telephone number of the corresponding advertising vendor. The retrieved telephone number may be used to place a call to that vendor automatically. The telephone number also may be stored for later use. The signals between the advertisement source and the wireless telephone may be transmitted as modulated infrared (IR) signals.
Hewlett-Packard Company has proposed a “Cooltown” project in which systems that are location-aware may be created using URL's for addressing, physical URL's for delivery via beacons and sensing of URL's for discovery, and localized web servers for directories. The systems are ubiquitous so that nomadic users may be supported. On top of this infrastructure, Internet connectivity may be leveraged to support communications services. Web presence bridges the World Wide Web and the physical world inhabited by the users, providing a model for supporting nomadic users without a central control point. In one implementation, a cooltown museum and Bookstore offers visitors a Web-enhanced experience. As visitors tour the museum, their portable digital assistant (PDA) may receive Web URLs from a set of distributed wireless beacons. These beacons are small infrared transceivers that may be located near pictures, sculptures, and other items of interest. Each beacon is configured to transmit signals containing the URL for a Web page containing information relating to the item associated with the beacon. In this scheme, a user may use a PDA's Web browser to read or hear information about the item of interest, such as information about an artist or a work and information about related art works in the cooltown museum. URLs also may be stored as bookmarks for further study or they may be used to select reproductions of the artwork from the museum's online store.
In one approach to providing a personalized interaction with a computer network, U.S. Patent Publication No. 2001/0021950 describes a network access control scheme in which interaction with a computer network is facilitated or restricted based on a portable tangible token that may be carried by a user. The token includes a machine-readable indication (or tag) that identifies the token and may be read wirelessly by a tag reader associated with a computer. The tag reader communicates the identifier to a computer connected to the network as a node. The computer, in response, determines and implements a network-access criterion based on the token. Generally, the computer maintains a database relating token identifiers to associated network-access criteria, and consults the database when presented with an identifier. The access criterion specifies information governing interaction between the computer and the network, and can serve to initiate connections or restrict them.